Process of concentrating ores and minerals by flotation



Patented Dec. 6, 1927.

UNITED STATES PATENT OFFICE.

WILLIAM A. DOUGLASS,

0F IPENNS GROVE, NEW JERSEY, ASSIGNOR TO E. I. DU PONT DE NEMOURS &COMPANY, OF WILMINGTON, DELAWARE, A CORPORATION OF DELAWARE.

No Drawing.

This invention relates to the recovery of valuable ores and minerals byflotation, and comprises more particularly the concentration of suchores and minerals by means of a certain class of organic flotationagents.

It is one of the ob ects of the present invention to carry out flotationprocesses in an efficient manner by the use of a class of flotationcompounds having highly selective properties. It is a further object tocarry out the flotation processes by the use of flotation agents whichare suitable for use in a neutral, alkaline or acid flotation circuit.

I have discovered that these and other objects may be attained by usingin the flotation process alkyl xanthogen formates. These compounds arecharacterized by having the following general structural formula s oaod-s-doa 3 O GIHI Oil-S- o CIHI As illustrative of the completeflotation process the following procedure may be carried out:

500 grams of ore and 350 cc. of water are ground in a ball mill for 20minutes and are then transferred to a J anney laboratory flotationmachine. The pulp is diluted in the machine so as to obtain a 38.5%solid pulp. The ethyl xanthogen ethyl formate and a frothing agent (pineoil) are added to the pulp and the mixture preagitated for one minute.The pulp is diluted to about a 20%- solid content, causing circulationand froth formation. The froth is removed over a seven-minute period.

Using Utah Copper Company and Anaconda Copper Mining Company ores, re-

CQNCENTRATING ORES AND MINERALS BY FLOTATION.

Application filed October 25, 1926. Serial No. 144,194.

spectively, the following results were obtained:

Using the same flotation reagent in the proportion of 0.10 pound per tonof ore, and carrying out the flotation process in the described mannerwith an Anaconda ore in a neutral circuit, the following results wereobtained:

Assay of heads=1.86% Cu.

Assay of Conct.=8.05% Cu.

Assay of tails=0.15% Cu.

Percent of total Cu recovered=93.6%.

In carrying out the flotation process with Anaconda ore in an acidcircuit containing sulfuric acid in the ratio of 8.0 pounds per ton ofore, and using as the flotation reagent, ethyl xanthogen ethyl formatein the rat-1o of 0.1 pound per ton of ore, the following results wereobtained:

Assay of heads=1.86% Cu.

Assay of Conct.=10.35% Cu.

Assay of tails=0.085% Cu.

Percent of total Cu recovered=96.2%.

These results are typical of results obtainable by using other alkylxanthogen formates suchas, for instance, the xanthogen formates ofpropyl, butyl, amyl, etc. By using these agents in the flotation processexcellent results are obtained and the process is susceptible of wideapplication.

The flotation reagents used in the present process may be prepared withcomparative ease. For example, ethyl xanthogen ethyl formate may be madeby suspending 21 gems of potassium xanthate in 75 cc. of

nzene 0 this sus ension are slowly added 10 grams of ethyl chIQrformate, vigorous agitation bein employed. The mixture is heated and hed at the refluxing temperature for four hours and then filtered toremove any unconverted potassium xanthate and the potassium chloridewhich is formed durin the reaction. The benzene is re move by vacuumdistillation, the residual oil being the ethyl xant-hogen ethyl formate.Any other suitable method may be used for preparing the flotationagents.

In illustrating the present rocess, reference has been made specifica lyto certain ores and reagents, and to various specific conditions ofoperation. It will be understood that the present process is not limitedto the specific substances or details of procedure mentioned, butincludes generally processes of recovering values from ores by flotationin which the flotation agents are compounds of the class described.Suitable modifications and changes may be made without departing fromthe spirit and scope of the invention.

I claim:

1. In the process of concentrating ores and minerals by flotation, theste which comprises subjecting the ore in t e form of a pulp to a frothflotation operation in the presence of an alkyl xanthogen formate. Inthe process of concentrating ores and minerals by flotation, the stepwhich comprises subjectin a pulp to a froth otation operation in thepresence of a substance having the following general structural formula:

in which R and R represent alkyl groups.

3. In the process of concentrating ores and minerals by flotation, thestep which comprises subjcctin the ore in the form of a pulp to a frothfl otation operation in the presence of ethyl xanthogen ethyl formats.

4. In the process of concentrating ores and minerals by flotation, thestep which comprises subjectin the ore in the form of a pulp to a frothotation operation in the presence of a substance having the followinggeneral structural formula:

in which R and R represent the same alkyl groups.

In testimony whereof I afiix my signature.

WILLIAM A. DOUGLASS.

the ore in the form of

